1. Field of the Invention
The present invention relates to a data communication system and a data managing method for managing a data move history of which contents data is moved between a server having a large storage memory and a terminal unit.
2. Description of the Related Art
EEPROM (Electrically Erasable Programmable ROM) that is an electrically rewritable non-volatile memory requires a large space because each bit is composed of two transistors. Thus, the integration of EEPROM is restricted. To solve this problem, a flash memory that allows one bit to be accomplished with one transistor using all-bit-erase system has been developed. The flash memory is being expected as a successor of conventional record mediums such as magnetic disks and optical discs.
A memory card using a flash memory is also known. The memory card can be freely attached to an apparatus and detached therefrom. A digital audio recording/reproducing apparatus that uses a memory card instead of a conventional CD (Compact Disc:Trademark) or MD (Mini Disc:Trademark) can be accomplished.
Since an audio recorder using a memory card as a record medium records and reproduces digital data, when the audio recorder uses a compressing method that allows data to be reproduced with relatively high quality, the copyright of music data and so forth that are recorded and reproduced should be protected. As an example, using encrypting technologies, memory cards that are not authenticated can be prohibited from being used. In other words, in a combination of an authenticated recorder and an authenticated memory card, encrypted data is decrypted.
Conventional memory cards do not have an encrypting function. Thus, to record confidential data to a memory card, the recorder should encrypt data and records the encrypted data to a memory card. However, when a decrypting key is stored in a memory card, the security of data cannot be protected. On the other hand, when a decrypting key is stored in the recorder, encrypted data cannot be decrypted by other than the recorder that has encrypted the data. Thus, the compatibility of the memory cards cannot be maintained. For example, data stored in a memory card of one user cannot be decrypted by a recorder of another user. To solve this problem, a system of which both a recorder and a memory card have respective encrypting functions and they authenticate each other for assuring the security of data and the compatibility of the cards has been proposed.
On the other hand, as digital audio/video information and multimedia systems are becoming common, a music data delivering service of which music data is delivered from a music data delivering server to a personal computer through a network such as Internet or a digital broadcast is being accomplished. In such a service, delivered contents data is stored in a hard disk of the personal computer. In addition, data reproduced from a disc such as a CD is stored in the hard disk.
In a system of which a hard disk is used as an audio server, audio data is moved from the hard disk to a memory card. With the memory card, the moved data can be reproduced by for example a portable player. In contrast, audio data is moved from the memory card to the hard disk of the server. For the purpose of the copyright protection and preventing data from becoming full, data is moved from the hard disk to a memory card so that the data is not left in the hard disk.
In the system of which a hard disk is used as an audio server, when data is moved from the hard disk to a memory card, all contents data of the hard disk is moved to the memory card. Thus, all the contents data in the hard disk is erased. In this method, since an encrypting process or the like is not required, the structure becomes simple and the data can be moved at high speed.
However, in the case that audio data recorded on a medium such as a CD is stored to a hard disk, the audio data is moved to a memory card, and then the audio data is returned from the memory card to the hard disk, the order of music programs returned to the hard disk is different from that of the CD. For example, when the user moves three music programs randomly selected from a CD (such as program numbers 2, 4, and 6) to a memory card, he or she listens to the music programs, and then he or she returns them to the server, the three music programs of the CD are erased from the copy source data. Instead, new data of the three music programs of the CD data is stored in the hard disk. However, the user usually expects that the hard disk manages the music programs in the same order of those recorded on the CD.
In the case that audio data recorded on a medium such as a CD is temporarily stored to a hard disk, the audio data is moved or copied from the hard disk to a memory card, and the audio data is copied from the memory card to another hard disk, the audio data can be unlimitedly copied to memory cards. Thus, the copyright of the audio data cannot be effectively protected.
An object of the present invention is to provide a data processing apparatus and method which can return contents formerly moved from the server to the original location when the contents are returned again to the server.
Another object of the present invention is to manage a data move source and a data move destination in the relation of one to one so as to prevent data from being illegally copied.
A first aspect of the present invention is a data communication system having an information source, a server, and a client, the server being connected to the information source and having a large storage medium for storing contents data supplied from the information source, the client storing the contents data moved from the large storage medium, wherein the client comprises a storing means for storing contents data moved from the server and move history management data for managing a history of the moved contents data, and a transmitting means for transmitting the move history management data to the large storage medium when contents data stored in the storing means is returned to the large storage medium of the server, and wherein the server comprises a creating means for creating management data for managing contents data whenever the contents data received from the information source is stored to the large storage medium, a controlling means for storing the management data created by the creating means to the large storage medium along with the contents data, a receiving means for receiving the move history management data from the transmitting means of the client, and an editing means for editing the management data when contents data stored in the large storage medium of the client is moved to the storing means of the client and for editing the management data corresponding to the move history management data received by the receiving means when contents data stored in the storing means of the client is returned to the large storage medium of the server.
A second aspect of the present invention is a data managing method for a data communication system having a plurality of contents titles, a server, and a terminal, the server having a large storage memory for storing management data for managing the plurality of contents titles, the terminal being connected to the server and moving a predetermined contents title from the large storage memory, comprising the steps of (a) creating move management data when a predetermined contents title is moved from the server, (b) transmitting the move history management data to the server when a contents title is returned from the terminal to the server, (c) referencing the management data stored in the large storage memory and the move history management data transmitted from the terminal when a contents title is returned from the terminal to the server, and (d) determining whether or not the contents title returned from the terminal is a contents title that has been stored in the large storage memory corresponding to the referenced result.